A fine circuit pattern is produced on a surface of a semiconductor wafer or glass substrate by a photolithographic step and an etching step. In the photolithographic step, a chemical liquid supplying apparatus is used to apply the chemical liquid such as photoresist liquid onto the surface of the wafer or glass substrate. By doing so, the chemical liquid accommodated in a container is sucked up by a pump, passes through a filter etc., and is applied from a nozzle onto a material to be applied such as a wafer. When particles such as dusts have been mixed in the chemical liquid to be applied, they adhere to the material to be applied, thereby causing pattern defects and resulting in lowering a yield of products. If the chemical liquid stays in the pump for a long term, it changes in quality. Therefore, since the chemical liquid changed in quality becomes particles in some cases, it is required that there is no chemical liquid accumulation in the pump for discharging the chemical liquid.
As the pump for discharging the chemical liquid, there is used such a pump that an expansion/contraction chamber in which the chemical liquid flows and a pump chamber are partitioned from each other by an elastically deformable partition membrane such as an diaphragm, tube, or the like. By doing so, the pump chamber is filled with indirect liquid, namely, an incompressible medium, and the chemical liquid is pressurized through the partition membrane. A pressurizing system for the incompressible medium includes a bellows-type system as described in Japanese patent application laid-open publication No. 10-61558 and a syringe-type system using a piston as described in U.S. Pat. No. 5,167,837.